Theoretical moment-curvature relationships for reinforced concrete members with cyclic loading are derived using stress-strain curves for steel and concrete. The theoretical curves compare well with test results and illustrate the variation in flexural stiffness due to the Bauschinger effect of the steel and to the presence of open cracks in the compression zone of the concrete which may eventually close. These cracks mean that for large portions of the moment-curvature curves after the first yield excursion the moment of resistance is provided by a steel couple alone. During this part of the cyclic loading the main role of the concrete is to prevent buckling of the steel. For beams with a marked difference between the top and bottom steel areas and for columns the moment-curvature loops show a pinching in effect and the loop area is significantly smaller than that of the commonly used elastoplastic idealization.